-47.66% is the change from 491 to 257
Calculation steps:
[( 257 - 491 ) ÷ 491] x 100 = -47.66%
Formula
Percentage change = [(257 - 491) / 491] x 100
Subtract the new number by the original number
257 - 491 = -234
-234 ÷ 491 = -0.47657841140529533
-0.47657841140529533 x 100 = -47.66%